pytorch

7073ee20 - Enable test_distributed for ROCm but only with nccl backend

Enable test_distributed for ROCm but only with nccl backend Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/28814 Differential Revision: D18437300 Pulled By: ezyang fbshipit-source-id: bf1ab68e0fde683e0082f6c9fe2fc20e2bc8fc06